In the case of headlights for automobiles and trucks, in order to generate a low beam, a diaphragm (“shutter”) is introduced into a beam path between a reflector and a lens of the headlight. The diaphragm blocks a portion of the light rays passing from the reflector to the lens, with the result that a sharp bright-dark boundary arises in the light emission pattern generated behind the lens in the far field. For headlights having an additional function, e.g. that of a high beam, a movable diaphragm has been used hitherto, one or the other light function being provided by the headlight depending on the position of the diaphragm. However, this arrangement is comparatively complex and in addition susceptible to wear.
US 2007/058386 relates to a method for producing a headlight module for a motor vehicle which emits a beam having a cut-off edge for producing a bright-dark boundary, including a lens and a light source in a rear region of the lens, from which it is separated by air in its arrangement, wherein the light source is formed by means of at least one LED, according to which the exit surface of the lens is chosen such that it can be connected to the exit surfaces of similar, adjacent modules at a smooth continuous surface, and the entrance surface of the lens is shaped such that the cut-off edge of the light beam is generated without a shielding diaphragm.
US 2004/136202 A1 discloses a vehicle headlight which uses a light emitting element, such as an LED, and has a projected light pattern. A light emitting surface of the light emitting element has a horizontally elongated form when viewed in a direction perpendicular to the optical axis of the light emitting element, in order thus to form a light distribution pattern which is magnified by an optical system, to be precise principally in a horizontal direction. Since the projected pattern is obtained by a magnification of the horizontally elongated light source, in this case it is easier to adapt the light distribution of the lamp than for the case where the light intensity distribution of the light emitting element is rotationally symmetrical.